Abstract:
Signal integrity is a major concern when designing printed circuit boards for high speed digital applications, and crosstalk is one of the most important issues. Crosstalk is influenced both by the routing geometry and the electrical parameters of the drivers and receivers on the board, and in order to keep crosstalk noise under control, minimum clearances must be enforced between sensitive and aggressive signal traces. However, the relationship between the crosstalk requirements (in electrical terms – usually [mV]) and the physical design rules (in geometrical terms – usually [mm]) is not very obvious and in order to evaluate it, some form of analysis must be involved. This paper proposes an algorithm designed to automate this process, based on differential impedance equivalence, implemented as a SAX Basic script and embedded into PADS Layout Editor.
